Review
Review
Review
Review
Review
100
Samuel adds a teaspoon of salt to a glass of water. He notices that the salt disappears. Samuel takes a sip to discover that the water tastes salty. What kind of change has occurred?
A. It’s a chemical reaction because a new substance has formed.
B. It’s a physical change because the water and the salt kept their original properties.
C. It’s an example of synthesis because two substances reacted to give one substance.
D. It’s a chemical reaction because the water now tastes salty but originally did not.
A. It’s a chemical reaction because a new substance has formed.
100
Carbon burns in the presence of oxygen to give carbon dioxide. Which chemical equation describes this reaction?
A. carbon + oxygen + carbon dioxide
B. carbon + oxygen → carbon dioxide
C. carbon dioxide → carbon + oxygen
D. carbon dioxide + carbon → oxygen
B. carbon + oxygen → carbon dioxide
100
Iron oxide reacts with aluminum to give aluminum oxide and iron. What kind of chemical reaction is this?
A. combustion
B. decomposition
C. replacement
D. synthesis
C. replacement
100
What kind of chemical reaction does the chemical equation sodium + chlorine → sodium chloride represent?
A. combustion
B. decomposition
C. single replacement
D. synthesis
D. synthesis
100
Calcium carbonate is a compound that is used to make chalk for drawing on rocks or pavement. One molecule has one atom of calcium (Ca), one atom of carbon (C), and three atoms of oxygen (O). Which is the correct way to write the chemical formula for calcium carbonate?
A. 3CaCO
B. Ca3CO
C. CaCO3
D. Ca3C3O3
C. CaCO3
200
Select the correct answer.
The picture represents sulfur trioxide.
Which statement is true for one molecule of sulfur trioxide?
A. There are three atoms of sulfur and one atom of oxygen.
B. There are three atoms of sulfur and three atoms of oxygen.
C. There is one atom of sulfur and one atom of oxygen.
D. There is one atom of sulfur and three atoms of oxygen.
D. There is one atom of sulfur and three atoms of oxygen.
200
If 
A. 
B. 
C. 
D. 
D.
200
Sodium bicarbonate is the chemical name for baking soda. Its chemical formula is NaHCO3. What does the subscript 3 mean?
A. There are three molecules of sodium bicarbonate.
B. There are three molecules of oxygen in sodium bicarbonate.
C. There are three atoms of oxygen in sodium bicarbonate.
D. There are three atoms of sodium bicarbonate.
C. There are three atoms of oxygen in sodium bicarbonate.
200
Which force causes a wagon to speed up as it rolls down a hill?
A. friction
B. gravity
C. mass
D. normal
B. gravity
200
A meteor is approaching Earth. Which statement about its motion is true?
A.The meteor accelerates.
B. The meteor travels upward relative to Earth.
C. The meteor falls with a constant velocity.
D. The meteor is out of Earth’s gravitational force field.
A.The meteor accelerates.
300
A spacecraft left Earth to collect soil samples from Mars. Which statement is true about the strength of Earth’s gravity on the moving spacecraft?
A. It increases.
B. It decreases.
C. It remains the same.
D. It doesn’t affect the spacecraft.
B. It decreases.
300
Jack tries to place magnets on his refrigerator at home, but they won’t stick. What could be the reason?
A. The body of the refrigerator isn’t made of magnetic material.
B. Earth’s magnetic field is interfering.
C. The magnet and the body of the refrigerator have like poles.
D. The refrigerator isn’t plugged into an electrical outlet.
A. The body of the refrigerator isn’t made of magnetic material.
300
Which electric component provides energy to the circuit of a flashlight?
A. motor
B. battery
C. resistor
D. switch
B. battery
300
John performs an experiment on an electric circuit. He increases the voltage from 25 volts to 50 volts while keeping the resistance constant. What will be the effect of John’s changes on the current?
A. The current will increase.
B. The current will decrease.
C. The current will stay constant.
D. The current will stop flowing.
A. The current will increase.
300
Elaine drew an electric circuit diagram that includes a door buzzer. But the current in the circuit is too high based on the parts she chose. Which part can Elaine add to lower the flow of current without changing the operation of the circuit?
A. a lightbulb
B. a motor
C. a resistor
D. a second battery
C. a resistor
400
Which method of testing substances is a sure way to identify a chemical reaction?
A. change in color
B. formation of bubbles
C. change in density
D. increase in temperature
E. solubility in water
A. change in color
400
Which chemical reaction absorbs energy?
A. photosynthesis
B. explosion
C. current produced by a battery
D. combustion of fuels
E. activated hand warmers
A. photosynthesis
400
A company develops a new synthetic product and prepares to sell it to the public. Customers ask questions about how to properly dispose of the product. Which word is related to disposal?
A. cost
B. performance
C. productivity
D. profitability
E. recyclability
E. recyclability
400
According to Newton’s law of universal gravitation, which statement is true?
A. Lighter objects experience a higher acceleration than heavier objects.
B. Falling objects accelerate as they approach the ground.
C. The weight of an object increases as it moves away from the ground.
D. Lighter objects experience a lower acceleration than heavier objects.
E. The mass of an object increases as it moves closer to the ground.
B. Falling objects accelerate as they approach the ground.
400
Robert is hosting a backyard barbecue. He uses a charcoal fire to grill the chicken. The chicken cooks, but it never touches the fire directly. What energy transformation occurs as the chicken cooks?
A. chemical potential energy → radiant energy → thermal energy
B. thermal energy → chemical potential energy → motion energy
C. chemical potential energy → electric potential energy
D. motion energy → chemical potential energy → motion energy
E. radiant energy → electric potential energy → chemical potential energy
A. chemical potential energy → radiant energy → thermal energy
500
Jay bought a toy car. To make the car move, he must turn a key attached to a spring. Turning the key winds the spring tight. The toy car moves when the key is released and the spring unwinds. What’s the main transformation of energy in this example?
B. chemical energy to motion energy
C. electric energy to motion energy
D. electric energy to potential energy
E. potential energy to motion energy
E. potential energy to motion energy
500
What’s the velocity of the rocket? Use .
A rocket with a mass of 10,000 kilograms is propelled upward with 8,000,000 joules of kinetic energy. The velocity of the rocket is () meters/second.
40 meters/second
500
Which object has the least amount of kinetic energy?
A. a car driving down a road
B. a soccer ball rolling down a hill
C. a bicycle locked to a bike rack
D. a satellite orbiting Earth
C. a bicycle locked to a bike rack
500
Why are some pots and pans designed with wooden handles?
A. Wood is a conductor.
B. Wood has a high heat capacity.
C. Wood is an insulator.
D. Wood is an organic substance.
C. Wood is an insulator.
500
If you heat soup on a stove, what happens to the movement of the soup’s particles?
A. The particles move slower.
B. The particles move faster.
C. There’s no change in the speed of particles.
D. The particles stop moving.
B. The particles move faster.